Showing 7 results for Emission
Kabiru Hannafi Ibrahim, Rossanto Dwi Handoyo, Abdul-Azeez Sani Baraya, Nur Istifadah,
Volume 0, Issue 0 (10-2025)
Abstract
Studies on trade and environmental pollution have explored the issue of pollution haven in goods and aggregate trade, but not in services. This study is therefore imperative, as it aims to examine the phenomenon of pollution haven in goods and services trade within the ECOWAS trading bloc from 2000 to 2023. The study examined whether developed countries have gained an advantage from open trade and transferred their polluting activities to ECOWAS member states. The study utilised panel data that comprised 15 member countries. Static and dynamic techniques of analysis were applied. Based on the theories underlying the analytical model, the results indicate that a rise in goods trade increases emissions. At the same time, services trade reduces emissions. The premise that trade shifts industry composition toward dirtier production is also supported. However, ECOWAS countries are exploring comparative advantages in labour-intensive industries that reduce pollution. Energy consumption exacerbates emissions, and trade in goods and services may bring energy-efficient technologies that lower pollution. ECOWAS countries are pollution haven in goods trade but not in services; that is, advanced economies use goods trade openness and transfer their pollution to the sub-region. These findings are further validated using other measures of pollution (GHG and PM2.5), enhancing the credibility and reliability of the research. Based on the study results, we provided policy implications to guide policymakers.
E . Izadpanah , A . Akhavan Taheri , M . H Hekmat , S . Talebi,
Volume 19, Issue 7 (8-2008)
Abstract
In this paper, the combination of conduction with radiation into a semitransparent medium which includes absorption, emission and scattering has been investigated. In order to Study the conduction in medium, the Non-Fourier heat conduction has been applied. In this model there is a time delay between heat flux and temperature gradient. Also, in contrast with Fourier heat conduction, the speed of heat propagation is finite. The radiation transfer equation has been solved via approximate method. Also to solve the energy conservation equation and Non-Fourier heat conduction simultaneously, flux-splitting method has been applied. The results show that the transient temperature responses are oscillatory for Non-Fourier heat conduction. Also the Non-Fourier effect can be important when the thermal relaxation time of heat conduction is large. In the initial times, the difference of transient temperature responses between the Fourier and the Non-Fourier heat conduction is large under this condition. For the laser-flash measurement of thermal diffusivity in semitransparent materials, omitting the Non-Fourier effect can result in significant errors.
Keywords:
Hossein Jandaghi, Ali Divsalar, Mohammad Mahdi Paydar,
Volume 30, Issue 1 (3-2019)
Abstract
In this research, a new bi-objective routing problem is developed in which a conventional vehicle routing problem with time windows (VRPTW) is considered with environmental impacts and heterogeneous vehicles. In this problem, minimizing the fuel consumption (liter) as well as the length of the routes (meter) are the main objectives. Therefore, a mathematical bi-objective model is solved to create Pareto's solutions. The objectives of the proposed mathematical model are to minimize the sum of distance cost as well as fuel consumption and Co2 emission. Then, the proposed Mixed-Integer Linear Program (MILP) is solved using the ε-constraint approach Furthermore, numerical tests performed to quantify the benefits of using a comprehensive goal function with two different objectives. Managerial insights and sensitivity analysis are also performed to show how different parameters of the problem affect the computational speed and the solutions’ quality.
Elham Moazzam Jazi, Hadi Abdollahzadeh Sangroudi,
Volume 31, Issue 1 (3-2020)
Abstract
Biofuels production systems are identified as a potential solution in responding to the ever-increasing energy consumption demand. The complexity of conversion process and supply chain of these systems, however, can make the commercialization of biofuels less attractive, so designing and management of an efficient biofuel supply chain network can resolve this issue. Hence, this paper proposes a multi-period hybrid generation biomass-to-biofuel supply chain considering environmental, economic and technology considerations. The objective is to maximize the total profit that biofuel producers can make with practical constraints including the biomass supply, the capacity of facilities, storage, Greenhouse Gas (GHG) emissions and transportation with limited capacity. To highlight the applicability of the proposed model, it is applied to a biomass-derived liquid fuel supply system in the southern region of Iran. In the case study, wheat and wheat stem are simultaneously considered as the first- and second-generation of feedstocks for biodiesel production. Sensitivity analyses show that available biomasses can have a significant impact on the profitability of this supply chain. The obtained results demonstrate the efficiency and performance of the proposed model in biodiesel supply chain design.
Zeinab Rahimi Rise, Mohammad Mahdi Ershadi, Mohammad Javad Ershadi,
Volume 33, Issue 1 (3-2022)
Abstract
Drawing lessons from the Covid-19 pandemic according to literature, this contribution aims to show that greening the United Nations System with stronger environmental considerations, can help to shift the global economy from fossil energy to renewable energy with public-health resilient systems. This contribution starts with highlighting the fact that past economic crises and the implementation of the Sustainable Development Global Agenda have not been able to generate strong institutional arrangements for sustainable development including climate resilience building and public health resilient systems. This allows us to apprehend the possibility that the Covid-19 pandemic crisis may face the same incapacity. In response to these statements, this contribution shares the opinion that institutional reforms within the United Nations System may lead to perennial normative provisions and institutional arrangements able to make sustainable development happen with resilient public-health systems. This note highlights the fall of GHZ emissions during the Covid-19 pandemic. It shows, however, based on the history of the past crisis, that the huge investment being mobilized to recover from the pandemic can quickly absorb GHZ emissions fall. The way out suggested is that both the Global Economy and the Global Public Health agendas can be revisited to be strengthened by stronger environmental considerations. One of our findings is that multilateralism can adopt suitable institutional arrangements in Global Environmental Governance throughout the current global agenda on International Environmental Governance Reform within the United Nations System.
Fatemeh Hajisoltani, Mehdi Seifbarghy, Davar Pishva,
Volume 34, Issue 1 (3-2023)
Abstract
The main objective of this research is effective planning as well as greener production and distribution of mineral products in supply chain network. Through a case study in cement industry, it considers the design of the mining supply chain network including several factories with a number of production lines and multiple distribution centers. It leaves part of the transportation operation to contractor companies so as to enable the core company to better focus on its products’ quality and also create job opportunities to local people. It employs a multi-period and multi-product mixed integer linear programming model to both maximize the profit of the factory as well as minimize its carbon dioxide gas emissions which are released during cement production and transportation process. Due to the uncertainty of its cost parameters, fuzzy logic has been used for the modeling and solved via a novel fuzzy multi-choice goal programming approach. Sensitivity analysis has also been done on some key parameters. Comparing results of the model with those from the single-objective models, shows that the model has good efficiency and can be used by managers of mining industries such as cement. Although leaving part of the transportation operations to contractor companies increases the number of vehicles used by the contractor companies, its associated decrease in the number of required factory vehicles, improves both objectives of the model. This should be considered by the managers since on top of profit maximization, it can help them build an eco-friendly image. Mining industries generally generate significant amount of pollutions and companies that pay attention to different dimensions of their social responsibilities can remain stable in the competitive market.
Dwi Kurniawan,
Volume 36, Issue 3 (9-2025)
Abstract
While traditional production planning focused on optimizing supply-demand balance through make-to-stock/make-to-order strategies and capacity management, the new imperative of carbon neutrality introduces critical complexities. Regulatory emission caps now require manufacturers to strategically trade carbon allowances, fundamentally transforming the challenges of production optimization. This study developed an aggregate production planning model that incorporates carbon trading constraints into operational decision-making, providing industries with a systematic approach to address both economic and environmental objectives. The model optimized multi-period production plans across alternative technologies, each with distinct cost-emission profiles, while incorporating subcontracting options. It simultaneously considered government-allocated emission permits, dynamic carbon market prices, technology-specific costs and emissions, and subcontracting expenses. Through mathematical optimization of production quantities, subcontracting levels, and carbon credit transactions, the model minimized total costs while ensuring compliance. Computational experiments with nonlinear programming solved via LINGO demonstrated the model's effectiveness in identifying optimal technology deployment strategies that achieve significant cost reductions while meeting environmental targets, offering manufacturers a powerful tool for sustainable operations in carbon-constrained markets.
